diff --git a/apps/api/src/routes/monitors.ts b/apps/api/src/routes/monitors.ts
index e481b99..de5d98d 100644
--- a/apps/api/src/routes/monitors.ts
+++ b/apps/api/src/routes/monitors.ts
@@ -36,7 +36,7 @@ export const monitors = new Elysia({ prefix: "/monitors" })
     }
 
     // Enforce minimum interval for plan
-    const interval = body.interval_s ?? 30;
+    const interval = body.interval_s ?? limits.minIntervalS;
     if (interval < limits.minIntervalS) {
       set.status = 400;
       return { error: `Minimum interval for ${plan} plan is ${limits.minIntervalS}s` };
diff --git a/apps/web/src/views/partials/monitor-form.ejs b/apps/web/src/views/partials/monitor-form.ejs
index c00201a..59484f2 100644
--- a/apps/web/src/views/partials/monitor-form.ejs
+++ b/apps/web/src/views/partials/monitor-form.ejs
@@ -69,7 +69,7 @@
       <select id="<%= prefix %>interval" name="interval_s"
         class="w-full <%= bg %> border <%= border %> rounded-lg px-4 py-2.5 text-gray-100 focus:outline-none focus:border-blue-500">
         <% intervals.forEach(function([val, label]) { %>
-          <option value="<%= val %>" <%= String(monitor.interval_s || '30') === val ? 'selected' : '' %>><%= label %></option>
+          <option value="<%= val %>" <%= String(monitor.interval_s || minInterval) === val ? 'selected' : '' %>><%= label %></option>
         <% }) %>
       </select>
     </div>